EP4061318A1

EP4061318A1 - Use of a glycine betaine derivative as an agent for conditioning keratin fibres

Info

Publication number: EP4061318A1
Application number: EP20816278.4A
Authority: EP
Inventors: Francis GALLE; Freddy PESSEL; Xavier Roussel
Original assignee: Surfactgreen SAS
Current assignee: Surfactgreen SAS
Priority date: 2019-11-22
Filing date: 2020-11-06
Publication date: 2022-09-28
Also published as: KR20220103937A; AU2020388133A1; JP2023503298A; US20220409507A1; CN114650806A; WO2021099715A1

Abstract

The present invention relates to a method for conditioning keratin fibres, comprising topically applying, to the keratin fibres, a cosmetic composition in the form of an emulsion containing, in a cosmetically acceptable medium, a surfactant composition containing at least one ester or amide salt of glycine betaine comprising from 14 to 24 carbon atoms. The invention also relates to the use of a surfactant composition as defined above as an agent for conditioning the keratin fibres.

Description

Use of a glycine betaine derivative as an agent for conditioning keratin fibers

OBJECT OF THE INVENTION

The present invention relates to the use as an agent for conditioning keratin fibers of a surfactant composition containing at least one ester or amide salt of glycine betaine comprising from 14 to 24 carbon atoms. It also relates to a process for conditioning keratin fibers, comprising the topical application to the keratin fibers of a cosmetic composition in the form of an emulsion containing, in a cosmetically acceptable medium, a surfactant composition as defined above.

BACKGROUND OF THE INVENTION

It is well known that hair which has been sensitized, in particular damaged and / or weakened, to varying degrees under the action of atmospheric agents or under the action of mechanical and / or chemical treatments, such as coloring, discolorations and perms are often difficult to disentangle, they lack discipline and their styling and shaping are particularly difficult. They may also lack shine, as their surface can be altered and can therefore reflect light less evenly.

To remedy these drawbacks, it is customary to have recourse to hair care which makes it possible to provide conditioning to the hair. These hair care compositions may be conditioning shampoos or conditioners which may be in the form of gels, hair lotions or more or less thick creams containing conditioning agents intended mainly to repair or limit the harmful or undesirable effects. induced by the various treatments or attacks to which the hair fibers are subjected more or less repeatedly.

Hair treatment compositions have already been proposed comprising cationic polymers and / or cationic surfactants as conditioning agents. These compounds are deposited on the hair and make it possible to improve the condition of the fibers and thus their cosmetic properties.

However, a number of these compounds are not completely environmentally friendly. There is therefore a need to develop cosmetic compositions which are less ecotoxic, or even non-ecotoxic, making it possible to condition the hair in a satisfactory manner, or even better than the compositions of the state of the art.

The Applicant has now discovered, unexpectedly and surprisingly, that certain glycine betaine derivatives could provide interesting conditioning properties to the hair. These compositions make it possible in particular to improve disentangling and straightening of the hair, as well as their flexibility; the shaping of the hair is easier, and the touch of the hair is very pleasant and fluid. These compounds also make it possible to confer similar properties on other keratin fibers, in particular on the beard.

In the cosmetics field, the salts of amides and esters of glycine betaine or the surfactant compositions containing them have already been described for their use in deodorants (WO 2015/003968) or in foaming shampoos with an acidic aqueous base (WO 2005/121291). Document WO 2015/078890 further discloses a surfactant composition obtained by reacting, in a first step, glycine betaine with an alcohol of formula RI —OH containing 1 to 6 carbon atoms, then with an alcohol of formula R2 Longer chain OH, in the presence of a sugar hemiacetal. This two-step process results in a complex surfactant composition containing, in addition to long-chain glycine betaine ester salts, corresponding shorter-chain esters, comprising a maximum of six carbon atoms, in a proportion always greater than 15% by weight. , as well as cationized alkylpolyglycosides. The composition obtained can in particular be used in the preparation of hair care products, in particular of a detangling spray.

To the knowledge of the Applicant, however, it has never been suggested to use long-chain glycine betaine ester or amide salts to promote disentangling of the hair, nor has it been proposed to use these compounds in a product. for conditioning keratin fibers, which is in the form of an emulsion.

SUMMARY OF THE INVENTION

The subject of the invention is the use as an agent for conditioning keratin fibers of a surfactant composition containing at least one glycine betaine derivative of formula (1): X ⁿ [(CH3) 3N ⁺ -CH2-COZ-R] _n where Z denotes an oxygen atom or a -NH group, R is a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 24 carbon atoms, X is an organic or inorganic anion, and n is 1 or 2.

It also relates to a process for conditioning keratin fibers, comprising the topical application to the keratin fibers of a cosmetic composition in emulsion form containing, in a cosmetically acceptable medium, a surfactant composition as defined above, it being understood that said surfactant composition does not contain alkylpolyglycosides.

DETAILED DESCRIPTION

The present invention relates to the application for conditioning keratin fibers of a surfactant composition based on at least one glycine betaine derivative, which is a long-chain glycine betaine ester or amide salt. These two types of glycine betaine derivatives, as well as their preparation processes will now be described in more detail.

The glycine betaine ester salts can be obtained according to a process comprising the successive steps consisting in:

(1) reacting glycine betaine or one of its salts with at least one linear or branched fatty alcohol, saturated or unsaturated, containing 14 to 24 carbon atoms, in the presence of an organic or inorganic acid;

(2) cooling the reaction medium to a temperature of 20 to 90 ° C; and

(3) recovering the surfactant composition thus obtained.

The first step in this process is to esterify glycine betaine, or trimethylglycine. Glycine betaine can be of plant or synthetic origin. It is necessary to protonate it beforehand using an organic or inorganic acid, insofar as it is in zwitterionic form (presence of a carboxylate function). The acid can in particular be chosen from inorganic acids such as hydrochloric acid, sulfuric acid, perhalohydric acids, such as perchloric acid, and mixtures thereof. As a variant, it can be chosen from organic acids, such as alkyl sulfuric acids, for example decyl or lauryl sulfuric acid; arylsulfonic acids, such as benzenesulfonic acid, paratoluenesulfonic acid; alkylsulfonic acids, such as triflic acid, methanesulfonic acid, ethanesulfonic acid, decylsulfonic acid, laurylsulfonic or camphosulfonic acid; sulfosuccinic acid; and their mixtures. Lewis acids can also be used. Preferably, it is an alkylsulfonic acid and in particular ethanesulfonic acid, insofar as it is easily biodegradable, or methanesulfonic acid.

During esterification, the acid function of the salified betaine is reacted with a fatty alcohol, to result in a glycine betaine ester in the form of a salt. By “fatty alcohol” is meant a linear or branched (preferably linear), saturated or unsaturated alcohol comprising from 14 to 24 carbon atoms. Examples of such fatty alcohols can be chosen from the group consisting of: myristic alcohol (04: 0), cetyl alcohol (06: 0), palmitoleic alcohol (06: 1), stearic alcohol ( 08: 0), oleic alcohol (08: 1), linoleic alcohol (08: 2), linolenic alcohol (08: 3), arachid alcohol (C20: 0), arachidonic alcohol ( C20: 4), behenic alcohol (C22: 0), 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol and mixtures thereof. Mixtures of fatty alcohols which can be used can be produced from one or more vegetable oils and in particular soybean, olive, sunflower, corn, palm, copra, cotton, flax, germ of wheat, safflower or rapeseed, for example.

It is preferred according to the invention to use one or more alcohols containing from 18 to 22 carbon atoms and more preferably a mixture of such fatty alcohols.

The esterification reaction is generally carried out in the absence of a solvent. The water produced during the reaction also contributes to the solubilization of the glycine betaine in the reaction mixture.

For carrying out this reaction, it is possible, for example, to use from 0.8 to 6.0 equivalents, preferably from 0.8 to 2 equivalents, for example from 0.9 to 1.0 equivalent, or as a variant of 1.1 to 1.8 equivalents, preferably in this case from 1.2 to 1.6 equivalents and, better, from 1.3 to 1.5 fatty alcohol equivalents or in a second variant from 4.0 to 6 .0 equivalents, preferably in this case from 4.5 to 5.5 equivalents and, better, from 4.8 to 5.2 equivalents of fatty alcohol.

Also advantageously used from 1.01 to 3.0 equivalents, preferably from 1.5 to 2.0 equivalents, for example from 1.5 to 1.9 equivalents, and preferably from 1.5 to 1.7 equivalents. molar of organic or inorganic acid, or alternatively (preferably in the second above variant) from 1.02 to 1.08 equivalents, preferably in cases from 1.03 to 1.07 equivalents and, better, from 1.04 to 1.06 molar equivalent of organic or inorganic acid for

I equivalent of glycine betaine. The esterification is carried out at a temperature ranging for example from 120 to 180 ° C, preferably from 150 to 180 ° C. The reaction can be carried out under atmospheric pressure or preferably under reduced pressure, for example at a pressure of 10 to 600 mbar. The pressure will generally be all the lower as the chain length of the fatty alcohol involved is great. The reaction medium is then cooled to a temperature of 20 to 90 ° C.

The surfactant composition thus obtained is then recovered, which contains at least one glycine betaine ester salt of formula X ⁿ [(CH3) 3N ⁺ -CH2-COOR] _n where: X is an organic or inorganic anion, R is a alkyl radical corresponding to the fatty alcohol R-OH used in the esterification reaction, and n is 1 or 2.

The anion X results from the acid used in the first step of the process and can therefore in particular be a chloride, a sulfate, a perchlorate, an alkylsulfate ion, in particular decylsulfate or laurylsulfate, an arylsulfonate ion, in particular benzene sulfonate , paratoluenesulfonate, an alkylsulfonate ion, in particular triflate, methanesulfonate, ethanesulfonate, decylsulfonate, laurylsulfonate, camphosulfonate, or a sulfosuccinate ion. It is preferred according to the invention for X to be chosen from alkylsulphonates and arylsulphonates, in particular from methanesulphonate, triflate, paratoluenesulphonate and camphosulphonate ions. It is advantageously the methanesulfonate or ethanesulfonate ion, more preferably the ethanesulfonate ion.

The R radical can for its part be chosen from the groups myristyl (04: 0), cetyl (06: 0), palmitoleyl (06: 1), stearyl (08: 0), oleyl (08: 1), linoleyl (08 : 2), linolenyl (08: 3), arachidyl (C20: 0), arachidonyl (C20: 4), behenyl (C22: 0), 2-hexyldecyl, 2-octyldodecyl and 2-decyltetradecyl.

It is understood that, in the case where several fatty alcohols are used in the esterification reaction, the surfactant composition obtained according to the invention will comprise several salts of esters of glycine betaine. The term "a glycine betaine ester salt" should therefore be understood, in the context of this description and unless otherwise indicated, as referring to one or more of these salts. The process described above makes it possible more precisely to obtain a surfactant composition containing the following constituents:

(a) at least one glycine betaine ester salt of formula (1): X ⁿ [(CH3) 3N ⁺ -CH2-COO-R] _n where R is a linear or branched, saturated or unsaturated alkyl group, comprising from 14 to 24 carbon atoms and preferably from 18 to 22 carbon atoms,

(b) at least one fatty alcohol of formula R-OH,

(c) an organic or inorganic acid of formula XH,

(d) a glycine betaine salt of formula X ⁿ [(CH3) 3N ⁺ -CH2-COOH] _n , and

(e) optionally, at least one dialkyl ether of formula R-O-R, where X is an organic or inorganic anion and n is 1 or 2.

This surfactant composition can be used as it is in the present invention. In this case, it generally contains 15 to 85% by weight of glycine betaine ester salt.

In a first variant, the surfactant composition contains:

(a) 65-85% by weight, preferably 70-80% by weight, glycine betaine ester salt

(b) from 1 to 20% by weight, for example from 1 to 9% by weight or from 10 to 20% by weight, of fatty alcohol,

(c) from 1 to 20% by weight, for example from 5 to 15% by weight of organic or inorganic acid

(d) from 1 to 20% by weight, for example from 2 to 15% by weight, of glycine betaine salt

(e) 0 to 15% by weight, for example 2 to 10% by weight, of dialkyl ether

In a second variant which is preferred, the surfactant composition contains:

(a) 15 to 45% by weight, preferably 20 to 30%, more preferably 25 to 30% by weight, of glycine betaine ester salt,

(b) from 55 to 80% by weight, for example from 60 to 65% or from 65 to 70% or from 70 to 80% by weight, of fatty alcohol,

(c) from 0 to 5% by weight, for example from 0 to 1% by weight of organic or inorganic acid

(d) 0 to 3% by weight, for example 0 to 1% by weight, of glycine betaine salt

(e) 0 to 15% by weight, for example 2 to 10% by weight, of dialkyl ether.

This composition can be obtained by carrying out the process described above, which uses an amount of fatty alcohol of between 4 and 6 equivalents and an amount of acid ranging from 1.02 to 1.08 equivalent, for one equivalent of glycine betaine. The composition obtained, which is found to be rich in alcohol and poor in acid, has several advantages over the composition according to the first variant, obtained using 1.1 to 1.8 equivalents of fatty alcohols and 1.5 to 2.0 acid equivalents. In fact, the presence of a smaller quantity of acid in the composition makes it possible to increase its naturalness and to reduce the quantity of pH corrector to be added during the formulation of the surfactant composition, the latter itself being liable to 'negatively impact the stability of the emulsion and certain properties conferred on keratin fibers. The performance of the surfactant composition is also improved by increasing the amount of residual alcohol that it contains.

Preferably, the weight ratio of the glycine betaine ester salt to the fatty alcohol is between 20:80 and 30:70.

Advantageously, the surfactant composition contains no other constituent than components (a) to (e) above. Alternatively, the above method can include an additional step of isolating the glycine betaine ester salt present in this composition, which can be used as such in the present invention. In the latter case, the surfactant composition used according to the invention will comprise at least 90%, preferably at least 95%, or even at least 99% by weight of glycine betaine derivative.

Glycine betaine amide salts

These glycine betaine derivatives can be prepared according to a process comprising the successive steps consisting in:

(1) reacting glycine betaine or one of its salts with a linear or branched, saturated or unsaturated, C4-C8 alcohol, in the presence of an organic or inorganic acid, at a temperature ranging for example from 100 at 180 ° C and under reduced pressure;

(2) cooling the reaction medium to a temperature of 20 to 80 ° C;

(3) adding one or more alkylamines containing 14 to 24 carbon atoms;

(4) removing residual alcohol; and

(5) recovering the surfactant composition thus obtained.

The first step of this process consists of an esterification reaction of glycine betaine, which can be carried out in a similar way to obtaining esters of glycine betaine, except that one or more alcohol (s) are used. linear (s) and / or branched (s) in C4-C8 in presence of the acid which can be chosen from those described above. Examples of such alcohols include butanol, pentanol, 3-methylbutan-1-ol (or isoamyl alcohol), fusel alcohol (mixture of pentanol, 2-methylbutan-1-ol and 3-methylbutan). 1-ol), hexanol, heptanol, octanol and mixtures thereof. By “butanol” is also understood in this description n-butanol, isobutanol and sec-butanol. Butanol, and more particularly n-butanol, as well as hexanol, are preferred for use in this invention, with hexanol being particularly preferred. This reaction is generally carried out in the absence of any solvent, the alcohol used constituting both the reagent and the medium. The water produced during the reaction also contributes to the solubilization of glycine betaine in the reaction mixture. It is generally possible to use from 1.1 to 20 equivalents, for example from 2 to 4 equivalents, of linear or branched C4-C8 alcohol and from 1.0 to 1.5 equivalents of sulfonic acid, for example of 1, 0 to 1, 2 equivalents and preferably 1, 1 equivalent of sulfonic acid, for 1 equivalent of glycine betaine. The esterification can be carried out at a temperature from 100 to 180 ° C, preferably from 100 to 160 ° C, more preferably from 120 to 150 ° C or from 130 to 160 ° C under atmospheric pressure or under reduced pressure.

The product of the esterification reaction may or may not be treated so as to separate the salt of the glycine betaine ester formed from the reaction medium. To do this, it is possible, for example, to filter the reaction medium, which makes it possible to separate the aforementioned salified ester, soluble in alcohol, from the other constituents which are not soluble.

One or more C14-C24 alkylamine (s) is then added either to the reaction medium or to the isolated ester. Examples of such amines are: tetradecylamine, hexadecylamine, octadecy amine, docosanylamine, eicosanylamine and mixtures thereof. It is preferred according to the invention to use one or more amines containing from 16 to 22 carbon atoms and more preferably a mixture of such amines.

In this step, the alkylamine is advantageously used in molten form. The amount of alkylamine (s) added may for example represent from 0.9 to 1.5 equivalents and preferably from 1.0 to 1.2 equivalents per 1 equivalent of glycine betaine initially used. This aminolysis reaction is typically carried out at a temperature of 50 to 180 ° C and preferably 120 to 140 ° C, under reduced pressure, for example under a pressure of 1 to 30 mbar. In parallel with the aminolysis reaction, the alcohol is removed by distillation under reduced pressure. The aminolysis reaction and the distillation are carried out for a period of 1 to 7 hours, in particular 3 to 5 hours.

The surfactant composition thus obtained is then recovered.

This process makes it possible to obtain a surfactant composition comprising:

(a) one or more glycine betaine amide salt (s) of formula (1): X ⁿ [(CH3) 3N ⁺ -CH2-CONH- R] _n where R is a linear or branched alkyl group, saturated or unsaturated, comprising from 14 to 24 carbon atoms and preferably from 16 to 22 carbon atoms;

(b) one or more alkylammonium salt (s) of formula (2): X ⁿ [NH3 ⁺ R] _n where R is a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 24 carbon atoms and preferably from 16 to 22 carbon atoms;

(c) one or more glycine betaine ester salts of formula (3): C ^h [(0¾) 3 N ⁺ -CH2-COOR '] _n where R' is a linear or branched, saturated or unsaturated alkyl radical, containing 4 to 8 carbon atoms; and

(d) glycine betaine of formula (4): (CH3) 3N ⁺ -CH2-COO; where X is an organic or inorganic anion and n is 1 or 2.

This surfactant composition can be used as it is in the present invention. In this case, it generally contains 60 to 98% by weight, for example 70 to 80% by weight, of glycine betaine amide salt. Component (b) can represent from 0 to 25% by weight, for example from 15 to 20% by weight, component (c) from 0 to 15% by weight, for example from 5 to 10% by weight, and the component (c) from 0 to 15% by weight, for example from 5 to 10% by weight, and constituent (d) from 0 to 5% by weight, relative to the total weight of the surfactant composition. Advantageously, this does not contain any other constituent than components (a) to (d) above. Alternatively, the above method can include an additional step of isolating the glycine betaine amide salt present in this composition, which can be used as such in the present invention. In the latter case, the surfactant composition used according to the invention will comprise at least 90%, preferably at least 95%, or even at least 99% by weight of glycine betaine derivative.

It is preferred in all cases that the surfactant composition containing an ester or amide salt of glycine betaine as defined above does not contain cationized or non-cationized alkylpolyglycosides and / or, in the case of esters (Z = O) that it is also free from glycine betaine derivative of formula (G) X ⁿ [(CH3) 3N ⁺ -CH2-COO-R] _n where R is a group linear alkyl, saturated or unsaturated, comprising from 1 to 6 carbon atoms, X is an organic or inorganic anion, and n is 1 or 2.

In a preferred embodiment, the surfactant composition according to the invention contains at least 90% by weight, preferably at least 95% by weight, or even at least 99% by weight, of ingredients of natural origin, such as calculated according to ISO-16128.

For the implementation of the present invention, a cosmetic composition is used in emulsion form containing a surfactant composition as described above. This emulsion can have a liquid or semi-liquid consistency, a soft consistency of the cream or balm type or a solid consistency of the stick type. It can be of the oil-in-water (O / W), oil-in-glycerin, water-in-oil (W / O), water-in-glycerin or multiple (for example W / O / W) type. This emulsion is preferably of the oil-in-water type. It generally contains from 1 to 8% by weight, and preferably from 1 to 4% by weight, of glycine betaine derivative used according to the invention.

This cosmetic composition can in particular be packaged in a tube, a pump-dispenser or a jar. As a variant, it can be packaged in an aerosol container, in order to ensure application of the composition in vaporized form. In the latter case, the cosmetic composition preferably comprises at least one propellant.

The cosmetic composition used according to the invention comprises a cosmetically acceptable medium, that is to say a medium compatible with keratin fibers and the skin, in particular with the hair and the scalp, and which does not generate skin irritation. the skin or scalp or other undesirable effect after application to keratin fibers.

This cosmetic composition comprises an aqueous phase comprising water, one or more cosmetically acceptable water-soluble solvents chosen from C 1 -C 4 alcohols, such as ethanol, isopropanol, tert-butanol or n-butanol, polyols such as glycerol, propylene glycol and polyethylene glycols, and mixtures thereof. As a variant, it can comprise a mixture of water and one or more of the aforementioned solvents. Preferably, the cosmetic composition has a total water content of between 5 and 95% by weight, preferably between 10 and 90%, for example between 40 and 85% by weight, in particular between 50 and 80%. by weight relative to the total weight of the composition. The pH of this composition generally varies from 3 to 9, preferably from 3 to 7, preferably from 3.5 to 6, and better still from 3.5 to 5. It can be adjusted within this range using a minus one pH adjuster, chosen for example from: sodium or calcium gluconate, sodium lactate, sodium glycinate, sodium citrate and lactic acid / sodium lactate, acetic acid / sodium acetate buffer solutions and gluconic acid / sodium gluconate.

It further comprises at least one fatty phase containing at least one fatty substance, so as to form an emulsion. Preferably, the fatty substance (s) are chosen from oils, pasty fatty substances, waxes and their mixtures. The term “oils” is understood to mean a compound which is liquid at ambient temperature (25 ° C.) and atmospheric pressure (10 ⁵ Pa) which, when it is introduced in an amount of at least 1% by weight in water at 25 ° C. C, is not at all soluble in water, or soluble in an amount of less than 10% by weight, relative to the weight of oil introduced into the water. The term "pasty fatty substance" means fatty substances with a reversible liquid / solid state change, exhibiting in the solid state an anisotropic crystalline organization and comprising, at a temperature of 23 ° C, a liquid fraction and a solid fraction, such as than vegetable butters. The term “wax” denotes, in the context of this description, a fatty substance which is solid at 25 ° C, with a reversible solid / liquid change of state, having a melting point generally between 30 and 160 ° C, preferably between 50 and 90 ° C, as measured by Differential Scanning Calorimetry (DSC).

Preferably, the cosmetic composition used according to the invention comprises at least one oil. As examples of oils, mention may in particular be made of fatty alcohols, fatty esters, hydrocarbons of vegetable or mineral origin, triglycerides and vegetable oils containing them, and mixtures thereof. As fatty alcohols, mention may in particular be made of branched and / or unsaturated C10-C20 fatty alcohols such as octyldodecanol and oleyl alcohol. Examples of fatty esters are the esters of acids and of monoalcohol chosen from: mono- and polyesters of saturated linear C2-C10 acids (preferably C6-C10) and of linear mono-alcohols saturated in C10-C18 (preferably C10-C14), mono- and polyesters of saturated C10-C20 linear acids and of branched or unsaturated C3-C20 mono-alcohols (preferably C3-C10); mono- and polyesters of branched or unsaturated C5-C20 acids and of branched or unsaturated C5-C20 mono-alcohols; mono- and polyesters of branched or unsaturated C5-C20 acids and linear C2-C4 monoalcohols. Examples of such fatty esters are in particular the mixture of caprate and coconut caprylate, ethyl macadamate, ethyl ester of shea butter, isostearyl isostearate, isononyl isononanoate, d isononanoate. ethylhexyl, hexyl neopentanoate, ethylhexyl neopentanoate, isostearyl neopentanoate, isodecyl neopentanoate, isopropyl myristate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, laurate hexyl, isoamyl laurate, cetostearyl nonanoate, propylheptyl capylate, disopropyl adipate, diethylhexyl adipate, diisopropyl sebacate and diisoamyl sebacate.

As hydrocarbons, mention may be made of squalane (C30), in particular vegetable squalane extracted from olive oil or by biosynthesis, and hemisqualane (05). Examples of triglycerides are triglycerides of C6-C12 fatty acids, such as caprylic and capric acid triglycerides and triheptanoin. Examples of vegetable oils are in particular wheat germ, sunflower, argan, hibiscus, coriander, grape seed, sesame, corn, apricot, castor, shea oils, avocado, olive, soybean, sweet almond, palm, rapeseed, cottonseed, hazelnut, macadamia, jojoba, alfalfa, poppy, pumpkin, sesame, squash, blackcurrant, evening primrose, lavender, borage, millet, barley, quinoa, rye, safflower, bancoulier, passionflower, muscat rose, echium, camelina or camellia .

The fatty substances can represent from 1 to 30% by weight, preferably from 5 to 25% by weight, and preferably from 10 to 20% by weight, relative to the total weight of the cosmetic composition.

The cosmetic composition used according to the invention can also comprise at least one usual cosmetic ingredient, in particular chosen from nonionic surfactants, cationic surfactants, anionic surfactants, amphoteric surfactants; sun filters; active agents such as vitamins, anti-dandruff agents, anti-seborrheic agents, anti-hair loss and / or hair regrowth agents; antioxidants; pearlescent and / or opacifying agents; pigments; the charges ; sequestering agents; thickeners; non-thickening polymers such as amino silicones and / or cationic polymers; the perfumes ; conservatives ; and their mixtures.

The organic acids which can be used in this composition exhibit a pKa less than or equal to 7, preferably less than or equal to 6, ranging in particular from 1 to 6, preferably from 2 to 5. According to a preferred embodiment, the or the organic acids are chosen from carboxylic acids, sulfonic acids and mixtures thereof. In particular, the organic acid (s) are chosen from a- and b-hydroxy acids such as lactic acid, citric acid, glycolic acid, salicylic acid, malic acid, tartaric acid and their mixtures, and more preferably citric acid or lactic acid.

Preferably, the anionic surfactants are chosen from salts of alkylcarbonylisethionic acid, such as those identified under the INCI names SODIUM COCOYL ISETHIONATE and SODIUM COCOYL METHYL ISETHIONATE; lactylic acid salts, such as SODIUM LAUROYL LACTYLATE; salts of N-acylated amino acids, such as SODIUM LAUROYL GLYCINATE, SODIUM LAUROYL SARCOSINATE, SODIUM LAUROYL TAURATE and SODIUM OLIVOYL GLUTAMATE; sulfated anionic surfactants, chosen in particular from alkyl sulfate salts, in particular SODIUM COCO SULLATE and POTASSIUM LAURYL SULLATE, C8-C14 alkyl ether sulfate salts such as SODIUM LAURYL ETHER SULFATE; soaps in the form of salts of carboxylic acids, in particular SODIUM OLIVATE and SODIUM PALMITATE; and alkyl ether carboxylic surfactants, such as lauryl ether carboxylic acids or sodium lauryl ether carboxylates.

The nonionic surfactant (s) used in the cosmetic composition are preferably chosen from: C8 to C40 alcohols, saturated or not, linear or branched, oxyethylenated comprising from 1 to 100 moles of ethylene oxide, preferably from 2 to 50, more particularly from 2 to 40 moles of ethylene oxide, preferably comprising one or two fatty chains; oxyethylenated vegetable oils, saturated or not, comprising from 1 to 100 moles of ethylene oxide, preferably from 2 to 50; (C8-C30) alkyl (poly) glucosides, optionally oxyalkylenated (0 to 10 EO) and comprising 1 to 15 glucose units; sucrose esters such as sucrose stearate and sucrose distearate, C8 to C40 alcohols, mono- or polyglycerolated, comprising from 1 to 50 moles of glycerol, preferably from 1 to 10 moles of glycerol; saturated or unsaturated, linear or branched, oxyalkylenated fatty acid amides C8 to C30; esters of C8 to C30 acids, saturated or not, linear or branched, and of polyethylene glycols; esters of C8 to C30 acids, saturated or not, linear or branched, and of sorbitol, preferably oxyethylenated; and their mixtures.

The amphoteric, preferably non-silicone, surfactant (s) used in the cosmetic composition used in the present invention may in particular be derivatives of secondary or tertiary aliphatic amines, optionally quaternized, in which the aliphatic group is a linear or branched chain comprising from 8 to 22 carbon atoms, said amine derivatives containing at least one anionic group such as, for example, a carboxylate, sulfonate, sulfate, phosphate or phosphonate group. Mention may in particular be made of alkyl (C8-C20) betaines, alkyl (C8-C20) sulfobetaines, alkyl (C8-C20) amidoalkyl (C3- C8) betaines and alkyl (C8-C20) -amidalkyl (C6- C8) sulfobetaines.

The cationic surfactant (s) optionally used in addition to the glycine betaine derivatives can be chosen from salts of primary, secondary or tertiary fatty amines, optionally polyoxyalkylenated, quaternary ammonium salts, and mixtures thereof.

The thickener (s) can be chosen from cellulose thickening agents, for example hydroxyethylcellulose, hydroxypropylcellulose and carboxymethylcellulose; gums of natural origin such as Tara gum (Caesalpinia Spinosa Gum) and guar gum and its derivatives, for example hydroxypropyl guar and hydroxypropyltrimonium guar chloride; gums of microbial origin, such as xanthan gum and scleroglucan gum; synthetic thickening agents such as crosslinked homopolymers of acrylic acid or acrylamidopropanesulfonic acid; nonionic, anionic, cationic or amphoteric associative polymers. Among the cationic polymers which can be used as thickening polymers, mention may be made more particularly of polymers of the polyamine, polyaminoamide and polyquaternary ammonium type, in particular cationic celluloses, cationic guar gums and homopolymers or copolymers of dimethyldiallyl-ammonium halides.

Examples of active agents which can be included in the composition according to the invention are sodium hyaluronate, tocopherol and its derivatives such as tocopherol acetate, panthenol, serine, glycerin, arginine, ceramides such as that 2-oleamido-1,3-octadecanediol, hydroxypropyl starch phosphate and mixtures thereof, without this list being limiting. Mention may also be made of hair conditioning agents such as silicones, in particular dimethicone and amodimethicone.

Method / Use

The cosmetic composition used according to the invention is in the form of a product for caring for keratin fibers, in particular a conditioner or a hair mask intended for treating the hair. In particular, it is intended for the treatment, and therefore preferably applied to, weakened and / or damaged hair, for example by treatments. chemical or mechanical, in particular by coloring, bleaching, perming or straightening or by brushing. It can also be used as a treatment cream shampoo, in particular antiseborrheic or anti-dandruff. This composition can constitute a rinse-out or leave-in product. It does not generally exhibit foaming properties. This composition can also be in the form of a product to be rinsed out, to be applied before or after coloring, bleaching, perming or straightening or alternatively between the two stages of a perm or straightening.

As a variant, the cosmetic composition according to the invention can be in the form of a beard care product.

The present invention relates more precisely to a cosmetic process for conditioning keratin fibers, comprising the topical application to the keratin fibers of a cosmetic composition in emulsion form as described above. By “keratin fibers” is meant the hair and body hair, in particular the beard and the eyebrows. The types of hair to which the composition according to the invention can be applied include Caucasian, African and Asian hair. They can be more or less curly or even frizzy. By “conditioning” is meant, in the context of this description, the improvement of at least one property of keratin fibers chosen from: their combability, their ability to disentangle, their softness, their flexibility, their shine and their workability. Preferably, the conditioning of keratin fibers does not include cleaning them. The composition according to the invention therefore does not generally constitute a shampoo.

The composition can be applied to dry or wet hair, and preferably to wet or damp hair, that is to say previously washed and rinsed hair. According to one embodiment, the method according to the invention consists in applying to the hair an effective amount of the cosmetic composition, optionally mixing the hair, optionally leaving the composition on the hair and rinsing. The exposure time of the composition on the hair can be between a few seconds and 15 minutes and preferably between 30 seconds and 5 minutes. The composition is generally rinsed off with water. A possible step of drying the hair can be implemented. In another embodiment, the method according to the invention consists in applying to the hair an effective amount of the cosmetic composition, optionally mixing the fibers, optionally allowing the composition to sit on said fibers, and optionally drying without prior rinsing. This process is more particularly intended to improve the combability and / or the softness and / or the suppleness and / or the workability and / or the shine of keratin fibers and / or to smooth them and / or to hydrate them and / or to reduce them. their static electricity. It is generally not suitable or intended for cleaning keratin fibers.

FIGURES

Figure 1 illustrates the combability of a lock of hair treated respectively with water and with compositions containing respectively a reference surfactant, a mixture of salts of esters of glycine betaine according to the invention and a mixture of salts of 'glycine betaine amides according to the invention.

Figure 2 is a diagram illustrating the softness of locks treated using compositions containing respectively a reference surfactant, a mixture of salts of esters of glycine betaine according to the invention and a mixture of salts of amides of glycine betaine according to the invention, by comparison with a commercial conditioner.

EXAMPLES

The invention will be better understood in the light of the following examples, which are given for illustrative purposes only and are not intended to limit the scope of the invention, defined by the appended claims.

Example 1 Synthesis of surfactant compositions based on glycine betaine ester salt

Glycine betaine (1.0 eq) and a mixture of fatty alcohols from 08 to C22 (1.4 eq) are introduced into a reactor. The setpoint temperature for the mixture is fixed at 170 ° C. and the pressure is reduced to a value of 60 mbar. Once the pressure and temperature setpoints have been reached, a 70% methanesulfonic acid solution (1.6 eq) is added to the reaction mixture. As soon as the addition is complete, the setpoint temperature is brought back to 150 ° C. and the pressure is maintained at a value of 30 mbar. Five hours after the start of the introduction of the acid, the reaction mixture is allowed to cool to 80 ° C., then the product is recovered, cooled to room temperature, and constitutes the surfactant composition according to the invention, which contains the following constituents:

Table 1

Synthesis of ethanesulfonic acid salts

Glycine betaine (1.0 eq) and a mixture of C 18 to C22 fatty alcohols (5.0 eq) are introduced into a reactor. The setpoint temperature for the mixture is fixed at 170 ° C. and the pressure is reduced to a value of 60 mbar. Once the pressure and temperature setpoints have been reached, a 70% ethanesulfonic acid solution (1.05 eq) is added to the reaction mixture. As soon as the addition is complete, the setpoint temperature is brought back to 150 ° C. and the pressure is maintained at a value of 30 mbar. Six hours after the start of the introduction of the acid, the reaction mixture is allowed to cool to 80 ° C., then the product is recovered, cooled to room temperature, and constitutes the surfactant composition according to the invention, which contains the following constituents:

Table 2 Example 2: Synthesis of surfactant compositions based on salts of amides of glycine betaine

Glycine betaine (1.0 eq), butanol (3.0 eq) and a 70% methanesulfonic acid solution (1.1 eq) are introduced into a reactor surmounted by a condenser. The mixture is heated to 140 ° C. under atmospheric pressure. At 3 h of reaction, a Dean-Stark filled with butanol is mounted on the reactor. The mixture is left under atmospheric pressure because the distillation of the water-butanol azeotrope is initially sufficiently large. After 3 additional hours of reaction, when the rate of distillation of the water-butanol azeotrope decreases, the pressure is reduced to 700 mbar in order to accelerate the elimination of water and allow the displacement of the equilibrium towards butyl ester of glycine betaine. The conversion rate is monitored by 1 H NMR analyzes.

The NMR method consists in producing a ¹ H spectrum of the sample dissolved in a CDCl ₃ / CD ₃ OD (1/1, v / v) mixture, taking the methanol signal as a reference at 3.31 ppm. The characteristic signals of the different compounds are then integrated: MsOGBOBu (4.35 ppm, s, 2 H), MsOGB (4.28 ppm, s, 2 H), butanol (3.53 ppm, t, 2 H), methanesulfonate (2.74 ppm, s, 3H), dibutyl ether (3.40 ppm, t, 4H), where XOGBOBu denotes the sulfonate salt of the glycine betaine ester formed and XOGB denotes the glycine betaine sulfonate formed . The characteristic signal of the methanesulfonate takes account both of the methanesulfonic acid present in the medium, but also of the methanesulfonate which is the counterion of glycine betaine and of butyl betainate mesylate (MsOGBOBu).

The reaction conversion rate is obtained using the integration values by the following calculation: where: g is the conversion rate

Ii is the integration value of the characteristic signal of compound i.

Once the conversion rate of the esterification reaction reaches 96%, the reaction mixture is allowed to cool to 60 ° C. During this cooling phase, the Dean-Stark assembly is replaced by a distillation assembly and the reactor is placed under pressure. reduced in order to remove part of the butanol and the traces of water remaining in the reaction mixture. Once the mixture has reached 60 ° C., the mixture of fatty amines C16-C22 (1.1 eq) previously melted is added. The reaction mixture is then heated to 150 ° C. under reduced pressure. The pressure is gradually reduced to 10 mbar. After complete distillation of the butanol (approximately 4 hours), the reaction mixture is recovered and constitutes the surfactant composition according to the invention, containing the following constituents:

Table 3

Synthesis of Ethanesulfonic Acid Salts Glycine betaine (1.0 eq) and hexanol (3.0 eq) are introduced into a reactor surmounted by a Dean-Stark filled with hexanol. Attached to the reactor cover is an isobaric pouring funnel containing a 70% solution of ethanesulfonic acid (1.1 eq). The mixture is stirred and heated to 150 ° C. under reduced pressure at 600 mbar. Once the reaction conditions are reached, the 70% ethanesulfonic acid solution is gradually introduced into the reaction mixture. Once the addition is complete, the pressure is lowered steadily to reach 400 mbar in order to accelerate the elimination of water and allow the shift of the equilibrium towards the glycine ester betaine. The conversion rate is monitored by 1 H NMR analyzes.

The NMR method consists in producing a ¹ H spectrum of the sample dissolved in a CDCl ₃ / CD ₃ OD (1/1, v / v) mixture, taking the methanol signal as a reference at 3.31 ppm. The characteristic signals of the different compounds are then integrated: EsOGBOCô (4.35 ppm, s, 2 H), EsOGB (4.28 ppm, s, 2 H), hexanol (3.53 ppm, t, 2 H), ethanesulfonate (2.82 ppm, q, 2 H), dihexyl ether (3.40 ppm, t, 4 H), where XOGBOC6 denotes the sulfonate salt of the glycine betaine ester formed and XOGB denotes the glycine betaine sulfonate formed . The characteristic signal of G ethanesulfonate takes into account both the ethanesulfonic acid present in the medium, but also ethanesulfonate which is the counterion of glycine betaine and hexyl betainate esylate (EsOGBOC6).

The reaction conversion rate is obtained using the integration values by the following calculation: where: r) is the conversion rate h is the integration value of the signal characteristic of compound i. Once the conversion rate of the esterification reaction reaches 96%, the reaction mixture is allowed to cool to 80 ° C. During this cooling phase, the Dean-Stark assembly is replaced by a distillation assembly and the reactor is placed under reduced pressure in order to remove part of the hexanol and the remaining traces of water in the reaction mixture. Once the mixture has reached 80 ° C., a mixture of fatty amines of C 16 to C22 (1.1 eq) previously melted is added. The reaction mixture is then heated to 150 ° C. under reduced pressure. The pressure is gradually reduced to 5 mbar. After complete distillation of the hexanol (about 4 hours), the reaction mixture is recovered and constitutes the surfactant composition, which contains the following constituents:

Table 4 Example 3: Detangling test (sensory test)

A comparative test was carried out for disentangling a lock of hair using an emulsion of fatty alcohol in water containing, as a conditioning agent, either a mixture of salts of glycine betaine esters in Cl 8 to C22 or a mixture of salts of C 16 to C22 glycine betaine amides according to the invention, or a conditioning agent, namely behentrimonium chloride (Varisoft ^® BT 85 from EVONIK).

The glycine betaine ester and amide salts corresponded respectively to the compositions presented in Table 1 of Example 1 and in Table 3 of Example 2.

These emulsions had the following composition:

Cetyl alcohol 6.00% -10.00% *

Conditioner (active ingredient) 3.00% Preservative 0.60%

Buffer solution qs pH 4, 0-5.0 Demineralized water QSP 100.00%

* In order to achieve a viscosity of 7,000 to 22,000 mPa.s (LV4, 20 rpm, 20 ° C)

All of these emulsions had the appearance of an opaque viscous cream.

Tap water (hardness 30 ° F, temperature: 37 ° C) was also used as a control.

To carry out this test, 2 locks of hair were moistened beforehand then wrung out and finally rubbed 15 times in the palm of the hand to tangle the hair. Ig of each product was then applied to one of the two wet locks which was then massaged 8 times over its entire length to distribute the product well. After 3 minutes of exposure time, the locks were rinsed with tap water and then wrung out by hand. After having placed them on a flat surface, the number of comb strokes necessary to obtain a strand that can be combed without constraint was measured. This procedure was repeated three times per product, on 3 different strands. Only one test was carried out with tap water (30 ° F). The results of these tests are illustrated in Figure 1. As emerges from this Figure, the glycine betaine ester salts according to the invention offer performance equivalent to the reference surfactant. The glycine betaine derivatives, however, exhibit greater biodegradability than the reference surfactant, are 100% biobased and their synthesis process is more respectful of the environment. Glycine betaine amide salts exhibit superior efficacy to ester salts.

A sensory analysis of the softness of the locks thus obtained was then carried out by a trained panel, by comparison with a lock treated in the same way as above, but with a commercial detangling product (Elsève ^® Total Repair Rapid Restore) containing the same rate of cationic conditioning agent (behentrimonium chloride) and having the same pH and substantially the same viscosity as the above emulsions.

The results of this evaluation are presented in Figure 2. As shown in this Figure, the locks treated with the cosmetic composition according to the invention containing glycine betaine ester salts are perceived as much softer than those treated with the composition. containing the reference surfactant and even with the commercial conditioner.

An additional test was carried out under the same conditions, using the surfactant composition presented in Table 2 of Example 1. All the results obtained are collated in the Table below:

Table 5

It is observed that the performance of this surfactant composition is even better than that of a similar surfactant composition but prepared in the presence of a lower quantity of fatty alcohol and a higher quantity of acid. Example 4: Detangling test (mechanical test)

Material and method

A Diastron ^® Fibra One device equipped with a comb is used to measure the work (in Joules) required to go through a lock of hair.

To do this, five calibrated locks (3.5 g; 28 cm) flat of bleached Caucasian hair are first washed with 1 ml of sodium lauryl ether sulfate solution (28% of active material). The locks are rubbed 20 times between the hands, then rinsed for 1 min 30 in water. This washing is then repeated twice, then the excess water is removed by wringing the wick 3 times between 2 fingers.

The device is set as follows:

Starting position: 75 mm Combing length: 200 mm Speed: 2000 mm / min

Three measurements are taken for each lock, namely one measurement after each rinsing step, then the average of the three measurements is calculated.

The same conditioning treatment (0.5 mL) is then applied to one side of each of the five strands, then the product is spread 10 times with two fingers before being applied (0.5mL) to the other side of the strand. wick then spread 10 times with two fingers. The locks are then each rinsed for 16 seconds in tap water (changing sides every 8 seconds). The excess water is removed by squeezing 3 times between 2 fingers with the same force. The locks were then again tested Diastron ^® as described above. They are then subjected to two successive rinses (passing under the water tap for 10 seconds then removing the excess water by squeezing 3 times between 2 fingers) and again passed through Diastron ^® after each rinsing. The average of the three measurements obtained is calculated.

For each wick, we then determine the percentage decrease in the force necessary for disentangling the wick, using the following formula: D = (W _{T -} Wo) / 100, where W _T is the work measured after treatment and Wo is the work measured before treatment. The average MD of the reduction percentages obtained for the five locks is then calculated. The conditioning products tested were as follows:

1- Surfactant composition according to Example 2, containing approximately 1% by weight of glycine betaine ester and 3% by weight of C1 822 alcohols,

2- Comparative surfactant composition, containing 1% by weight of nonionic surfactant (sorbitan stearate) and 3% by weight of C1822 alcohols,

3- Comparative surfactant composition, containing 1% by weight of behentrimonium chloride as cationic surfactant and 3% by weight of C1822 alcohols,

4- Comparative surfactant composition, containing 1% by weight of cetrimonium chloride as cationic surfactant and 3% by weight of C.sub.1822 alcohols, where “C.sub.1822 alcohols” denotes a mixture of fatty alcohols containing from 18 to 22 atoms carbon (Stenol ^® 1822A from BASF).

Results

The results of the tests described above are collated in Table 6 below.

Table 6

As emerges from this table, the product according to the invention (product 1) gives the treated locks ease of disentangling, which results in the reduction of the work measured for combing the locks. This is of the same order as that obtained with a non-biodegradable cationic surfactant which is usually used in disentangling products (product 3) and higher than that obtained with a commercial cationic surfactant having a lower biodegradability than the product according to the invention (product 4). The performances of the product according to the invention are also much better than those obtained with a nonionic surfactant (product 2). Example 5: Formulations

Several types of products can be prepared using surfactant compositions according to the invention, based respectively on ester or palmitic amide (GBE 06: 0 or GBA 06: 0), stearic (GBE 08: 0) salts. or GBA 08: 0), arachidic (GBE C20: 0 or GBA C20: 0), or behenyl (GBE C22: 0 or GBA C22: 0) or mixtures thereof, and more particularly esters according to the second variant of l invention, containing at least 55% by weight of fatty alcohol.

Examples of such products are given below, the ingredients in capital letters being identified by their INCI names.

Hair conditioner :

Hair mask : 2 in 1 solid shampoo:

2 in 1 liquid shampoo: Hair straightening product:

Treatment after hair coloring: Solid conditioner:

Beard balm:

Claims

1. Cosmetic process for conditioning keratin fibers, comprising the topical application to the keratin fibers of a cosmetic composition in emulsion form containing, in a cosmetically acceptable medium, a surfactant composition containing at least one glycine betaine derivative of formula (1): X ⁿ [(CH3) 3N ⁺ -CH2-COZ-R] _n where Z denotes an oxygen atom or an -NH group, R is a linear or branched, saturated or unsaturated alkyl group, comprising 14 with 24 carbon atoms, X is an organic or inorganic anion, and n is 1 or 2, it being understood that said surfactant composition does not contain alkylpolyglycosides.

2. Method according to claim 1, characterized in that the radical R is chosen from myristyl (04: 0), cetyl (06: 0), palmitoleyl (06: 1), stearyl (08: 0), oleyl ( 08: 1), linoleyl (08: 2), linolenyl (08: 3), arachidyl (C20: 0), arachidonyl (C20: 4), behenyl (C22: 0), 2-hexyldecyl, 2-octyldodecyl and 2- decyltetradecyl.

3. Method according to claim 1 or 2, characterized in that the anion X is chosen from a chloride, a sulfate, a perchlorate, an alkylsulfate ion, in particular decylsulfate or laurylsulfate, an arylsulfonate ion, in particular benzene sulfonate, paratoluene sulfonate, an alkylsulphonate ion, in particular triflate, methanesulphonate, ethanesulphonate, decylsulphonate, laurylsulphonate, camphosulphonate, or a sulphosuccinate ion, preferably from alkylsulphonates and arylsulphonates, more particularly from methanesulphonate, triflosulphonate, xphenesulphonate, paratoluenate, and better still The methanesulfonate or ethanesulfonate ion, more preferably X is the ethanesulfonate ion.

4. Method according to any one of claims 1 to 3, characterized in that the surfactant composition contains the following constituents:

(b) at least one fatty alcohol of formula R-OH,

(c) an organic or inorganic acid of formula XH, and

(d) a glycine betaine salt of formula X ⁿ [(CH3) 3N ⁺ -CH2-COOH] _{n '} where X is an organic or inorganic anion and n is 1 or 2.

5. Method according to claim 4, characterized in that the surfactant composition contains:

(c) from 0 to 5% by weight, for example from 0 to 1% by weight of organic or inorganic acid,

(d) from 0 to 3% by weight, for example from 0 to 1% by weight, of glycine betaine salt,

(e) 0 to 15% by weight, for example 2 to 10% by weight, of dialkyl ether.

6. Method according to any one of claims 1 to 3, characterized in that the surfactant composition contains the following constituents:

(c) one or more glycine betaine ester salts of formula (3): X ⁿ [(CH3) 3 N ⁺ -CH2-COOR '] _n where R' is a linear or branched, saturated or unsaturated alkyl radical, containing 4 to 8 carbon atoms; and

7. Method according to any one of claims 1 to 6, characterized in that the surfactant composition comprises at least 90%, preferably at least 95%, or even at least 99% by weight of glycine betaine derivative.

8. Method according to any one of claims 1 to 7, characterized in that the keratin fibers are chosen from the hair, the beard and the eyebrows.

9. Method according to claim 8, characterized in that the composition is applied to weakened and / or damaged hair, for example by chemical or mechanical treatments, in particular by coloring, discolorations, perms or straightening or by brushing.

10. Method according to any one of claims 1 to 9, characterized in that it is intended to improve the combability and / or the softness and / or the suppleness and / or the workability and / or the shine of the keratin fibers and / or to smooth them and / or to hydrate them and / or to reduce their static electricity.

11. Method according to any one of claims 1 to 10, characterized in that the cosmetic composition is applied to previously washed and rinsed hair.

12. Use as conditioning agent for keratin fibers of a surfactant composition containing at least one glycine betaine derivative of formula (1): X ⁿ [(CH3) 3N ⁺ - CH ₂ -COZ-R] _n where Z denotes a oxygen atom or an -NH group, R is a linear or branched, saturated or unsaturated alkyl group comprising from 14 to 24 carbon atoms, X is an organic or inorganic anion, and n is 1 or 2.